Mortgage prepayment calculator
Estimate payment, term and interest savings after an early repayment
Enter the original loan, payments made and extra principal, then choose payment or term reduction.
Excludes booking dates, penalties, minimum amounts and lender approval rules.
Calculation result
Example
Input
Original CNY 1,000,000 · 30 years · 60 paid · prepay CNY 200,000
Example result
Balance, revised payment or term, and estimated interest saved
Interest saved does not subtract penalties or other costs.
Technical details & limits
Computes the old-plan balance, subtracts prepaid principal, then recalculates at the new rate. The shorter-term option targets roughly the old payment.
About this tool
Estimate the balance, revised payment or term, and remaining interest after a mortgage prepayment.
Use cases
- After a lump-sum prepayment, compare cutting the payment against shortening the term.
- Estimate how much total interest a prepayment saves.
- Recheck the outstanding principal and remaining schedule after a number of instalments.
How to use
- Enter the original principal, term, instalments already paid and the original rate.
- Enter the prepayment amount and the rate that applies afterwards.
- Choose what to do with the saving: lower the payment or shorten the term.
Notes
Whether a prepayment is allowed, any penalty, and how long you must wait are all set by your loan contract and are outside this page. The maths uses a fixed-rate model and ignores differences between payment and interest-accrual dates.
FAQ
- How does the mortgage prepayment calculator find the remaining principal?
- The tool models the outstanding balance from original principal, rate, term, repayment method, and elapsed periods, then deducts the prepayment. An original 240-period loan with 60 periods completed has 180 periods remaining before the adjustment. Verify the actual account balance if there were arrears, charges, or special changes. The modeled amount assumes the original schedule was followed and may not reproduce every transaction recorded by the lender.
- How do reducing the payment and shortening the term differ after prepayment?
- Reducing the payment retains the remaining term, while shortening the term recalculates duration around the original repayment level. With 180 periods remaining, a prepayment first reduces principal before either of these 2 scenarios is modeled. The result also depends on the entered new rate and repayment method. Confirm the actual arrangement with the lender, since its contract rules and available options may differ from the mathematical scenarios shown here.
- Do displayed prepayment interest savings include penalties and processing fees?
- Displayed interest savings exclude prepayment penalties and processing fees. If the model saves 10000 but the contract charges 2000, account for that charge separately when comparing the net financial effect. Those figures are examples rather than expected charges. Review the actual payment date, contractual fees, and complete cash flows before interpreting a modeled interest reduction as the total benefit of using funds for early repayment.
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